This link helped me solve my problem. Specifically adding
location / {
try_files $uri $uri/ /index.php?q=$uri&$args;
#try_files $uri $uri/ =404;
}
to the corresponding configuration file in /etc/nginx/sites-available
worked for me!
I have a wordpress site and when I use Arabic characters for the url address of my page I get a 404 Error but when I rename the link name for my page with english characters it works!
I found this question here but the solution there did not work for me! It makes sense that this is related somehow to .htaccess file, but I already have other wordpress sites which are working with arabic urls and have the same .htaccess content!